<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>圆角</title>
    <style>
        .box1{
            width: 100px;
            height: 100px;
            background-color: rgb(46, 207, 247);
            /* border-radius: 20px; */
            border-start-start-radius: 30px;
            border-end-end-radius: 30px;
        }

    </style>
</head>
<body>
    <div class="box1"></div>
   
</body>
</html>